I've long held firm on the belief that car dealers are the lowest life form in society. The very epicenter of these multi million dollar enterprises is the service dept. This is where the perfect storm of increasingly more complicated cars and naive owners that think a dealership cares for anything except their money meet. My story begins with my 2019 Sierra needing a catalytic converter at just 110k miles. After looking around online I came across an aftermarket one, not knowing that most GM trucks can't use aftermarket, you'll have an engine light after this is installed but at least its drivable. I brought it to Mastria to have it diagnosed and sure enough it was the aftermarket cat and an O2 sensor. They were able to clear the light (and noted the new cat was welded in and they didnt know how to get it out, crackheads do it in under a minute in the dark with no special tools or lift) and I had to drive it for 125 miles for the ECM to reset so I could go for inspection. I did this and brought it back, only to be told it now needs tires. They never mentioned this days earlier when they had it. They gave me a quote for tires. I saved about $500 buying online and having them installed locally. In this time the engine light came back on. So I emailed looking for a quote on the OEM cat, which was ignored so I went in person and was handed a quote for $3700 including 6 manifold nuts at $7 each with the parts counter telling me these are needed when changing a cat out. These are just everyday flare nuts, nothing special and the stock ones are just as reusable as any other nut on a vehicle. At this point I started to consider using the $3-4,000 as a down-payment to trade in so I started browsing their site and see a $698 "documentation fee" tacked on to all auto sales, on top of tax and title. Can you imagine being so full of yourself you charge people a fine for choosing to do business with you?! In a state that banned junk fees these guys charge more than a month's truck payment LMAO. Anyway back to the cat. Looking around online I found the exact same OEM cat 45 mins away at Tasca Parts Online for $1,000 less. No other parts or hardware I didn't need added on. I did have to pay $440 shipping which they refunded when I picked up the new part at their store in Cranston. Yari over there was great to deal with and kept me informed on where the part was throughout the process. I paid to have it put on at a custom exhaust shop and its all fixed at last. While this experience made me a "one and done" GM owner it was great to work with someone that saved me so much. Words of advice when dealing with dealerships, especially ones like Mastria. -Always get a second opinion, especially when they start trying to sell you a credit card. Dealers didn't earn the "stealership" label accidentally. -Shop around. -Check consumer reports to see where the brand stands and why. GMC is #23 of the 26 auto brands for overall satisfaction. No domestic brands even made the top 7. GMC is only staying profitable due to "high margin" truck sales, a fancy way of saying "grossly overpriced". -Do your research on potential big ticket repairs, had I seen all the forums and enthusiast pages talking about this exact item I would have stayed with Toyota (#1 on Consumer Reports list) read more